Explosive.



; s eer GS'WALB SILBE .,RAD, F BUCKHURST HILL, ENGLAND.

nxrriosivn.

i Specification of Letters Patent.

Patented July 7, 1914;

No Drawing. Original application filed June 3, 1912, Serial No. 701,2l2. Divided and this application filed November 23, 1912. Serial No. 783,196.

To all whom it may concerm Be i known that I, OSWALD SILBERRAD, Ph. D. a subject of the Kingof Great Britain and Ireland, director. of the Sil berrad Research Laboratories, and residing at Buckhurst Hill, in the'county of Essex, England, have invented certain new and of explosives, and has for its object to produce a plastic explosive by means of liquid nitra-ted hydrocarbons obtained by nitrating a liquid neutral product of coal tar, boiling between about 200 C. and 350 C. The nitration products for use in the explosive can be produced from any or all or any; liquid neutral fraction of the following coal tar products, viz.,-'the oils boiling between about 200 C to about 350 (3., that is to say, the'liquid portions of middle-heavy and anthracene oils, the residues'from the manu} facture of carbolic acid,creosote, naphthalene and anthracene, and also coal tar lubricarting oil. The oils preferably used are those of which at least the greater portion boils between 200 C. and 270 C. The nitration is eilected as, described in my application for Letters Patent Ser. No. 701242, of which this applicafiled June 3rd, 1912, tion is a division.

I have found that by taking that fraction of tar (or of any of the oils or residues obtained in the industrial treatment of tar) which boils'at 200 C. to 270 C. or thereabout, and subjecting it to the treatment set.

' methylated naphthalenes. The product conlows 1-4000 parts naphthalene. Not only is this product itself non-Volatile and liquid, but being essentially composed of.derivatives of the naphthalene series, it is capable of dissolving a large quantity of highly nitrated compounds of the benaene-series (as trinitrotoluene) which are of themselves solids, and as the final solution remains liquid, it is particularly suitable for the manufacture of safe plastic explosives of great power and quite perma nent.

i in manufacturing an explosive according to one example, a suitable still is charged with the creosote oil, containing the residue from the manufacture of carbolic acid and naphthalene, and that fraction is collected boiling from 200 to 270 C. After freeing the distillate from any naphthalene which separates out, it is subjected to chemical washing with alkali and acid, using sufficient alkali to remove all phenolic bodies 1n the first place, then water, then sulfuric acid, then dilute alkali, and finally water again. V

In effecting the Washing, l find it convenient to subject the oil to a thorough washing with 2=}-% to 5% concentrated oil of vitriol, and to repeat this operation until the desired degree of purity is obtained,

to 2092 of acidbeing used in this manner.

The washing with concentrated sulfuric acid serves to remove hydrids, as for example, hydro-naphthalene derivatives, acenaphthalene, and anthracene derivatives of the acetylene series and'other'unsaturated and unstable substances, which Ihave found are present in this product from coal tar andjwhich react with violence on nitration and become oxidized. After washing, the oil is again distilled, and the fraction boiling between 200 C. and 270 C. again col-' lected, allowed-to stand and freed fromany further quantity of naphthalene which separates. The oil is now ready for nitration, in order to effect which I proceed as follows: The nitration ma be carried out as fol-v y volume' of 'oil prepared as above boilingvbetween 200 C. and 260 C. is run into a suitable nitration vessel fitted with agitator and cooling jacket. A mixture of 100 parts by volume of nitric acid of 1.5 sp. gr. with 25- parts of Water are gradually run in. Then 100 parts by volume of nitric acid of sp. gr. 1.5 previously diluted 'witlr10 parts of water are gradually added. Then 100 parts by volume of nitric acid 1.5 sp. gr. previously di-' luted with 5 parts of water are gradually added. Then. 100 parts by volume of nitric acid of 1.5 sp. gr. is. gradually added; and

finally 150 parts by volume of nitric acid of 1.5 sp. gr. previously mixed with 450 parts by volume of concentrated sulfuric acid are gradually added.

During the-whole operation the contents of the vessel are kept under violent agitaa suitable vessel containing clean Water, preferably about times its'bulk, and also a few lumps' of marble or the like are added, and the mixture gently boiled under the re flux condenser until. all unstable compounds are decomposed. This is. generally satisfactorily .accom "Jlished in from 24 to 18 hours.

Instead o soda-ashI may -.use the car'- Jaonates or bicarbonates or. hyd'roxids of any of the alkali metals or mixtures containing any or all of these; similarly in place of" marble I. may usechalk, dolomite, magnesia or the carbonates or hydroxide of any or all of the alkaline earths.

' In producing an explosive by the use of the nitratedproduct so produced, a suitable quantity of soluble nitrocellulose or collodion cotton is added, gelajtinization is effect ed by the aid of heat, and a suitable proportion or oxygen. bearing salts is added. If desired, highly nitrated compounds of the benzene series, such as crude tri-nit'ro toluene may be added in comparatively large quantities for the nitrated product being a derivative of the naphthalene series iscapable of dissolving a comparatively pounds of the benzene series.

The following 1s an example of an explos1ve made 'a'ccordmg to my invention Parts. Nitr'o hydrocarbons as dscribedabove- 1O Highly nitra'ted compounds of the henzene series (as crude di and tri-nitro toluene) t i 20 Soluble nitro-cellulose or collodion-cotton s- 0.5 Oxygen bearing salts as potassium chlorate 70- VVith or with out preservatives or wood meal.- For this purpose, I find the followin oxy i large quantity of thesehighly nitrated com- I gen bearing salts suitable :-The nitrates and perchlorates of potassium, sodium or ammonium, the chlorates of potassium or sodium, or any mixture of these; but I find it desirable to avoid any mixture containing a chlorate together with an ammonium salt, as I find such a combination is likely to become unstable.

Similarly, the nitro hydrocarbops above described may be utilized with. other eX-' plosives.

What I claim is 1. A, plastic explosive containing as an ingredient a liquid nitro product consisting essentially of nitro-derivatives of methylated naphthalenes, as set forth.

" 2 A plastic explosive containing as an ingredient a liquid nitro product consisting essentially of dmitro derivatives of methylated naphthalenes as set forth.

r 3. A plastic explosive contalnmg the following ingredients, viz.,'liquid nitro derivatives of methylated na'phthalenes, highly nitratedhydrocarbons of the benzene series,

soluble nitro-cellulose, and oxygen bearing salts, as set forth.-

' In testimony whereof I have signed my name to this specification in the presenceof two subscribing witnesses.

OSWALD SI'LBERRADr- Witnesses:

J. W. PALCHING E. C. T1 1onr.

Copies of this. patent may be obtained for five cents each, by.addressing the Commissioner of Patents Washington, D. 0. I 

